Bog

[SDuster11]

We took the boat out yesterday to see how everything worked and good and bad news. Good news the motor didn't fall off. Bad news the boat couldn't get up on plane. To get youll up to speed its a 10' GW with a 70Hp Inline 3 Merc. The motor would idle with out sign of dieing but it seemed a little bit rough. Once I put it in gear it would still idle alright but when I tried to give it gas it was obvious that some thing wasn't right. Even with a few minutes of trying different methods of accelerating nothing really happened.

Came home did a compression check and all 3 cycl. ranged from 117-125 psi. With the plugs out i stuck the plug wire on them and fired it over and all proved to have spark. We had just replaced a piston so that was why we checked compression so quickly. I was thinking we might have messed up the timing in putting it back together. Or it coul be a fuel problem, the motor/carbs have set inside for approximately 4-5 years, does this ring any bells?

I was hoping that someone had run into this before and could set me straight. Thanks for all you'lls help,
Dustin

[Brabender]

Sounds Like carbs to me. Rebuild them and try again

[Riverratt]

could also be the fuel pump diaphram. not familiar with your motor but I had an inline 115 acted the same way and the diaphram was bad.

[astro1800]

make sure your ignition timing is advancing right. may not be getting the amount of timing you need for the gas your putting in

[mercmatt22]

Id start with carbs thats a long time for them to sit. Put a new water pump in it just to be safe.

[SDuster11]

I messed with it today and checked the timing the best I could, it was like 45 degrees ATDC at idle BUT idle was at around 2500 RPM then when I reved it once the timing jumped to about 6 degrees ATDC and I looked up in the manual and the idle should be set about 650 RPM with 6-8 degrees ATDC and 23 degrees BTDC at 5500 RPM. My question is do I simple remove the fllywheel, set number 1 cyclinder at TDC of the stroke and then place the flywheel back on aligning the TDC mark on the wheel with the pointer? That's where I leaning to right now. Will that help out with the idle? Because I backed the idle adjustment all the way off and it didn't seem to make any difference. thanks,
Dustin

[SportJ-US-1]

Sounds to me like you have a flywheel problem. Does this flywheel/crank use a key or is it splined? Either way it should go on only in one position. If it's keyed and not torqued right you can spin the wheel on the crank, very bad. Could also be loose magnets in the flywheel, seen that before too.

[Rickracer]

If they have sat that long, at very least pull them apart and clean them. I think you'll probably find your problem if you do a synch and link, right by the book, unless someone has a better procedure. :cool:

[SDuster11]

Okay pulled the flywheel off and reset the motor #1 at TDC and put it all back together. Fired it up and at idle which is right at 1200 RPM (instead of 2500 last night) i had about 3* BTDC so i'm wandering if i COULD get the idle to about 650 RPM my timing would prolly be just about right. Only thing is my idle adjustment is all the way out. Is there another adjustment that I'm missing? thanks,
Dustin

[Rickracer]

If so, set the timing right by the procedure in the manual. If there is anything sticking, binding, or out of adjustment, the procedure should correct it. :cool:

[Riverratt]

the 650 rpm is probably supposed to be in gear under load I would think which will make it idle around 900 on the muffs in neutral

[Rickracer]

If these adjustments are being made on muffs, the idle will be considerably higher. :cool:

[SDuster11]

Adjustments are being made under the muffs so would that mean an idle of about 1200 in gear would be close to right? thanks,
Dustin

[Rickracer]

...it would be much closer. When you're on the muffs, there is no backpressure, so the idle will be considerably higher. :cool:

[Riverratt]

I would think it should be around 1000 or less on the muffs. 1200 sounds high

[mercmatt22]

if it is at 1200 by the boat tach i may not be to high i have seen alot of boat tachs that are off by 100-300 rpms. so if the boat tach is reading 1200 you might be at 1000 best bet is to use another tach either get a timing light w/one on it or a multimeter w/ a tach setting i just ordered a hand held tach from snap on $250 (kinda high if you dont use it all the time) But i would do what rick said clean the carbs and do a synk and lynk.

[Rickracer]

....at least not until you put it in the water and see how it does then. :cool:

[SDuster11]

Well after I thought I had the timing corrected I put it in the water and the same problem. So as you'll said I pulled the carbs off and cleaned them (eventhough they appeared to be very clean inside) put them back on tried it out and still......... bog. :mad: So now i'm left scratching my head. I could have messed up the timing but I followed the manual and set it up step by step. I'm kinda at a loss of what to do now. But what keeps blowing my mind is that in nuetral you rev it and it revs up quick as hell as soon as u put it in gear you can just tell something ain't right. Will putting it in gear put that much of a load on it? thanks,
Dustin

[Capt.Insane-o]

The cylinder bores straight?, did you seal the cankcase halves properly?, idle mixture screws set right? It could be many many things. Like all merc inlines, if the bores are'nt straight, it is'nt going to run. Generally, if you can get it to idle at at 950-1000 rpm's on the hose, it will be dang close once you put it in the water.

[mercmatt22]

are you positive that you could flow fluid through all the passages in the carbs.

[SDuster11]

I'm almost certain that we got the crankcase halves to seal off properly. And I got the idle down to I believe 1200 rpms on the muffs in gear, never was able to check it in the water b\c of the tach not working (mess with that once he bog problem is ironed out)

As for me being sure I could get fluid through all the passages in the carbs....... What I did was pulled the carbs off, pulled the bowl off, took out the needle and seat, made sure they were clear and clean, then pulled out the air to fuel screw\jet and cleaned it did I skip something I may have over looked? thanks,
Dustin

[mercmatt22]

it is always best to soak the carbs. then blow them out good w/air blow air through all passages then take some spray b-12 and spray it through all the passages if you just cleaned the bowl, needle+seat and the idle mix screw you could have trash in the passageways that control your off idle operation.

[SDuster11]

Well I took it to a local Merc Guru and had him look it over, and he found that my primer bulb was not acting properly and he felt that I was running to high a pitch of prop(21) He had a 14 Pitch prop lying around and tried it out and it actually was able to get on plane and run good according to him. Well after he put the prop on it I built a jackplate for it and put at on also (raisied the motor bout 4 inches) and tried that. This time put it in and she got on plane fine and seemed all is well. (have the motor in the 1st notch tilted out) and when I laly into it the front of the boat kinda shoves in the water

I experimented with kicking the motor out on the 2nd notch and it did much the same.
On the third notch it jumps out of the hole perty good and on plane she pops pretty good like the motors kicked out to far but when you lay into it she narrows up and is real smooth but it still feels like the front of the boat is shoving into the water. What should I do? I dont' have tilt or trim and can't afford that right now either. I do have the option of putting one of those "whale tales" is what I call them what are the pro's and cons of that?